Bladder cancer (or bladder carcinoma) is prevalent in developed countries, particularly among men. Bladder cancer is also the fifth most common cancer and results in significant morbidity and mortality. Bladder cancer is notoriously among the most aggressive tumours as soon as they reach stage 2 (T2). Early detection and monitoring of early stage bladder cancer (Ta, T1 stages) patients is critical since these tumours are well-known to recur with high frequency and ultimately progress to T2 stage.
Early detection of bladder cancer requires invasive procedures for confirmed diagnosis. For example, cystoscopy and cytology are still the gold standards for the detection and follow-up of bladder carcinoma. However, these methods cannot detect certain lesions, such as small carcinoma in situ, and are often employed whenever patients present with other clinical signs.
As non-invasive urinary tests are highly desirable for both patient and healthcare system, multiple attempts to develop bladder cancer biomarkers have been made in order to substitute or complement invasive diagnosis such as cystoscopy.
New biomarkers, based on DNA methylation profiling, point mutations and microRNAs, have been established in addition to many proposed protein biomarkers for use in detecting bladder cancer. Commercially available urine-based diagnostic protein markers have also been developed. However, so far, none of the single biomarker assays known in the art adequately address early detection of bladder cancer. For example, tests that measure Nuclear Matrix Protein 22 (NMP22) and Bladder Tumour Antigen (BTA) are currently available commercially and have been approved by the U.S. Food and Drug Administration (FDA) for bladder carcinoma diagnosis. However, these tests rely on single-marker assays that are known to lack specificity.
As none of the single biomarker assays known in the art adequately address early detection of bladder cancer, there is a need to provide an alternative assay that is able to address early detection of bladder cancer. For example, two multiplex protein signatures of ten biomarkers or eight biomarkers have been developed and known in the art. However, none of these currently available diagnostic marker assays have offered sufficient sensitivity and specificity to be routinely used in the clinic.
In view of the above, there is a need to provide an alternative bladder cancer protein biomarker. There is also a need to provide an alternative detection system for non-invasive detection of bladder cancer in a patient. There is also a need to provide an alternative method of determining whether a patient suffers from or shows recurrence of bladder cancer or early stage bladder cancer or late stage bladder cancer.